BALTIMORE (WJZ)— Baltimore state’s attorney is speaking out following the controversy over no charges filed in a deadly accident right in front of City Hall.

Mary Bubala has the latest on this case.

Gregg Bernstein let the driver of an out-of-control car that crashed and killed a long-time city employee walk with no charges.

On Thursday he explained why.

“You need to be very careful with these kinds of cases,” Bernstein said.

Bernstein says it takes time to build a case like this. Toxicology reports and accident reconstruction need to come in first.

On Tuesday, Matthew Hersl was leaving work at City Hall when authorities say a speeding car slammed into him, killing him.

The driver wasn’t arrested despite police and witnesses reporting he was traveling more than 100 mph.

But a reckless driving charge now could prevent prosecutors from filing vehicular manslaughter once all the evidence is in.

“You have to be careful that you’re not charging something that later will prevent you from going forward in the future,” Bernstein said.

“I was very surprised,” said Ed Norris.

The decision to wait on charges is being criticized by the former police commissioner and now CBS Radio host Ed Norris.

“I know the prosecutor’s office put out that it takes time to build a vehicular manslaughter case and a lot of investigation needs to take place and that’s true, but that’s usually true in cases when you don’t witness it,” Norris said.”You have a state trooper who is a witness. I have no idea why you release this guy.”

But prosecutors say it’s standard procedure.

When Johns Hopkins student Miriam Frankl was hit and killed in 2009, the suspect wasn’t arrested until a week later — even with witnesses.

“We need to be sure that when we make a decision about what charges we’re going to file that they are supported by the evidence,” Bernstein said.

The family of Hersl is preparing to bury the beloved community leader.

“We’re humbled and greatly appreciate all the people who showed love for Matt. We want to thank everyone,” a loved one said.

Bernstein says no weapons or drugs were found in the car that hit Hersl. If they had been found they could have filed charges in connection with that while investigators built the traffic case.